Signal-horn.



" narran srarns artnr wormen.

BOSCH, F STUTTGART, GERMANY, A. CORPORATION 0F GERMANY.

SIGNAL-HORN.

Specification' of Letters Patent.

Patenten apr. io, ieri.

` To all whom it may concern.'

v eo

Be it known that l, GoTTLoB HoNoLD, a subject of the Emperor of Germany, residing at and whose post-oiiice address is Militaerstrasse 4 6, Stuttgart, Germany, have invented certain new and useful Improve-4 ments in Signal-Horns; and I do hereby declare thevfollowing to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which A it appertains to make and use-the same.l

Heretofore in employing a vibratile dia' phragm to generate air waves `for producing sound signals, Vthe controller for effecting the rapid interruption of the flow from the source of power supply to the operating mechanism for vibrating the diaphragm has beenfast'enedto the diaphragm. For instance, in anelectromagnetic, device of thiskind, the diaphragm carried one of the coperative contacts in the circuit between the battery andthe winding of the electro# magnet, or the diaphragm carried a lever which vibrated on the diaphragm .in response to movements thereof to control the electric circuit.. Similarly,'in the case of pneumatically operated horns, the controller carried by the `vibrating diaphragm isI in the from of a valve or the like. llnall these cases, the movement-of the diaphragm ,is damped by the controller, either by periodically striking la rigid or yielding -abutment forming a circuit .contact or valve member,

or by the weight and yimpact of the springI lever mounted on it.v The damping action reduces the volume `of the sound, or increases the power required for a given volume, and it sometimes produces in addition a discordant sound as a result of theinterfering waves generated by the variation of the movement of the diaphragm from free or impeded vibration. ln accordance with my invention, the vibratilediaphragm of the signal horn gives aclear note of large volume with comparatively small expenditure of energy.- l ob tain this result by removing the power controller from. the vibratile diaphragm 'and' producing 'the rapid' vibration of the diaphragm by means of a controller responding to the wave action set upl thereby to periodi- Preferably, a horn of suitable form is arranged in suitable relation to the'l vibratile diaphragm Iand is tuned to the notey of the vibratile diaphragm .or to an overtone therek diaphragm.

- GOTTLOB HONOLD, 01E' STUTTGART, GERMANY, ASSIGNOR T0 THE FIRM 0F ROBERT of, while the controller is carried by the horn in' suitable relation to the wave set up'` 60 in the air within the horn.v In this way,l

the vibratile diaphragm produces vibration I of the controller of like period and of like phase to thereby ma'ntain the natural pe# riod` of vibration of lthe diaphragm durin the note emitting period. The controller may, according to my invention, control a valve of a pneumatically operated system, or, as shown hereinafter, it may produce. a rapid interruption in the flow of electric current to an electromagnet acting on the vibratile diaphragm to generate the sound waves.`

In the accompanying drawings, I show, partly in-longitudinal section and partly diagrammatically, the lelectromagnetically operated typ'e of. signal horn, as an example, Figures l and 2 illustrating theI arrangement with open end horns in which fundamental and thethird overtones are used respectively; and Fi ..3 illustrating the arrangement'with 'a c osed end horn in which `the first. overtone is used. l

, IReferring vto 1, the vibratile diaphragm a is held rigidly around its edge and carries an iron armatureb at'its center responsive to magnetic attraction of thev electromagnetic core cv Iupon excitation by current flowing through the wlnding d from the' battery "e. 'lhelhorn g has one end in' proximity'to the diaphragm a, and is in the prises a vibratile member h held. rigidly around its edge and having an electric conv tactz' fastened at itsv center so as to coperate with the stationary contact c. The circuit connections include the wires w andthe handvv operated switch or push button f.

The modification shown in Fig. 2 is simi-l lar'to that of Fig. 1, except that a longer horn g is used, the third overtone of the note 0f the horn being in resonance with the note produced by the vibratile diaphragm a.

The modification shown in Fig. 3 is the preferred form, since by using a closed end horn g, as shown, the horn is but half the length of the open end horn for the same note. In the drawings, the horn has a note corresponding to the first overtone of the note produced bythe vibratile diaphragm a, and the horn is closed at its outer end by the vibratile controller k which, as before, carries the electric contact z'l cooperative with the stationary contact c in the circult of the electromagent winding d.

In the drawings, the broken lines l represent the stationary waves set up in the c olumn of air in -resonance with the waves produced by the vibratile diaphragm a. In Fig. 1, the center of the vibratile controller L is opposite the node y of the wave, and in Fig. 2, the center of the vibratile controller la. is likewise opposite a node m of the wave. In Fig. 3, the vibratile controller h is placed at a node m of the wave, and the controller b is located at the end of the pipes since there is a node at this point.

It Will be observed that in all cases, the horn g is tuned to the vibrations of the air wave Z so that. ampliiication of the sound volume is secured by resonance of the horn. Furthermore, the central points of the vibratile diaphragm-a and the vibratile controller h are separated along the axis or wave l by adistance equal to a multiple of the wave length, these two members vibrating synchronously and remaining in phase during vibration.

The operation of the three modifications is the same. Normally, the switch f is open and the vibratile controller 71. occupies an unstressed position in which-the contacts i and k are engaged. Upon closing the switch f, the vibratile diaphragm a is attracted by the electromagnet, which is then excited by current flowing into the winding al from the battery e, andthe air wave generated produces a simultaneous movement of the controller h in a direction to separate the contact i from the Contact c. The electric circuit 'then being open, the vibratile diaphragm a springs back to its normal position and the vibratile controller z. again closes the circuit at the coperative contacts. The diaphragm a is thereupon attracted again, and the vibration thereof continues as long as the switch f is held closed, the controller h vibrating synchronously, and in phase therewith as a result lof the variation of pressure at the node point at which the vibratile controller is located. In this way, the vibratile diaphragm 'a produces with a comparatively small expenditure of energy,

a clear tone which is amplified by the horn to produce a signal of intense volume, suitable for a warning for automobiles, motor boats and analogous purposes.

Having thus described my invention, what I claim is:

l. In a signal horn, a vibratile diaphragm, operating mechanism for the diaphragm, a source of power supply, a horn in proximity to the diaphragm, and a vibratile controller carried by the horn and vibratedby air waves generated by the diaphragm, said controller effecting a rapidly interrupted flow from the source of power supply to the operating mechanism.

2. In a signal horn, a vibratile diaphragm, operating mechanism for the diaphragm, a source of power supply, a tuned vibratile controller synchronously vibrated by the air waves generated by the diaphragm and effecting a rapidly interrupted flow from the source of power supply vto the operating mechanism.

3. In a signal horn, an electromagnet, a vibratile diaphragm magnetically responsive to the electromagnet, a source of current supply, a horn in proximity to the diaphragm, a vibratile controller carried by the horn and vibrated by air waves generated by the diaphragm, and circuit connections including coperative disengaging contacts one of which is carried by the controller to efect a rapidly interrupted flow from the source of current supply to the winding of the electromagnet.

4. In a signal horn, a vibratile diaphragm, operating mechanism for the diaphragm, a source of power supply, a horn having one end in proximity to the diaphragm, and a vibratile controller covering the other end of the horn, said controller being vibrated by air waves generated by the diaphragm and effecting a rapidly interrupted flow from the source of power supply to the operating mechanism.

`5. In a signal horn, a vibratile diaphragm, operatin mechanism for the diaphragm, a source o power supply, a horn in proxlmity to the diaphragm, and a vibratile controller vibrated by air waves generated by the diaphragm and effecting a rapidly interrupted flow fr om the source of power supply to the operatlng mechanism, the controller being tuned with the diaphragm and being arranged to interrupt the flow from the source whenever the diaphragm is actuated by the operating mechanism.

6. In a signal horn, an electromagnet, .a vibratile diaphragm magnetically responsive to the electromagnet, a source of current supply, a horn having an open end in proximity to the diaphragm, and bein arranged along the axis .of vibration o the diaphragm, a vibratile controller covering the outer end of the horn end 7`vibrated by air In testimony whereof I aix my signa# Waves generated by the diaphragm, and oirture. cuit connections including cooperative contacts one of which is carried by the con- GOTTLOB HONOLD 5 troller to effect a 'rapidly interrupted flow Witnesses:

from the source of current supply to the PAUL WoLFAsT,

Winding of the electromagnet. ADoLF LEBHERS. 

